What should I know about lebensmittelunvertraglichkeit wie testen?

The question about food intolerance testing is important, but the scientific evidence for many direct-to-consumer tests (e.g., IgG blood tests for foods) is weak. The provided knowledge base does not contain specific information on food intolerance tests; it covers DNA tests for skin aging and hormone analysis. In general, some intolerances (like lactose intolerance) can be reliably tested via genetic markers (e.g., LCT polymorphism) or breath tests. Others, such as non-celiac gluten sensitivity or histamine intolerance, lack validated consumer tests. Many commercial 'IgG food intolerance' tests are not recommended by medical societies because they often yield false positives and lead to unnecessary dietary restrictions. Evidence-based medicine recommends symptom-guided diagnostics under medical supervision. Without specific studies or guidelines in the context, consumers should be skeptical of such tests and consult a doctor before making major dietary changes.